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authorMark Brown <broonie@linaro.org>2013-10-25 10:51:29 +0200
committerMark Brown <broonie@linaro.org>2013-10-25 10:51:29 +0200
commit8211e6b8facd9d0da3e8f6e51657cba8b0af19da (patch)
tree2f73c2ae7cbbab24bd93998f6f63264eee5c1269 /drivers/spi/spi.c
parentMerge remote-tracking branch 'spi/topic/imx' into spi-next (diff)
parentspi/s3c64xx: Use core message handling (diff)
downloadlinux-8211e6b8facd9d0da3e8f6e51657cba8b0af19da.tar.xz
linux-8211e6b8facd9d0da3e8f6e51657cba8b0af19da.zip
Merge remote-tracking branch 'spi/topic/loop' into spi-next
Diffstat (limited to 'drivers/spi/spi.c')
-rw-r--r--drivers/spi/spi.c130
1 files changed, 129 insertions, 1 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 99c05f639e1b..8d05accf706c 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -39,6 +39,9 @@
#include <linux/ioport.h>
#include <linux/acpi.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/spi.h>
+
static void spidev_release(struct device *dev)
{
struct spi_device *spi = to_spi_device(dev);
@@ -525,6 +528,95 @@ int spi_register_board_info(struct spi_board_info const *info, unsigned n)
/*-------------------------------------------------------------------------*/
+static void spi_set_cs(struct spi_device *spi, bool enable)
+{
+ if (spi->mode & SPI_CS_HIGH)
+ enable = !enable;
+
+ if (spi->cs_gpio >= 0)
+ gpio_set_value(spi->cs_gpio, !enable);
+ else if (spi->master->set_cs)
+ spi->master->set_cs(spi, !enable);
+}
+
+/*
+ * spi_transfer_one_message - Default implementation of transfer_one_message()
+ *
+ * This is a standard implementation of transfer_one_message() for
+ * drivers which impelment a transfer_one() operation. It provides
+ * standard handling of delays and chip select management.
+ */
+static int spi_transfer_one_message(struct spi_master *master,
+ struct spi_message *msg)
+{
+ struct spi_transfer *xfer;
+ bool cur_cs = true;
+ bool keep_cs = false;
+ int ret = 0;
+
+ spi_set_cs(msg->spi, true);
+
+ list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+ trace_spi_transfer_start(msg, xfer);
+
+ INIT_COMPLETION(master->xfer_completion);
+
+ ret = master->transfer_one(master, msg->spi, xfer);
+ if (ret < 0) {
+ dev_err(&msg->spi->dev,
+ "SPI transfer failed: %d\n", ret);
+ goto out;
+ }
+
+ if (ret > 0)
+ wait_for_completion(&master->xfer_completion);
+
+ trace_spi_transfer_stop(msg, xfer);
+
+ if (msg->status != -EINPROGRESS)
+ goto out;
+
+ if (xfer->delay_usecs)
+ udelay(xfer->delay_usecs);
+
+ if (xfer->cs_change) {
+ if (list_is_last(&xfer->transfer_list,
+ &msg->transfers)) {
+ keep_cs = true;
+ } else {
+ cur_cs = !cur_cs;
+ spi_set_cs(msg->spi, cur_cs);
+ }
+ }
+
+ msg->actual_length += xfer->len;
+ }
+
+out:
+ if (ret != 0 || !keep_cs)
+ spi_set_cs(msg->spi, false);
+
+ if (msg->status == -EINPROGRESS)
+ msg->status = ret;
+
+ spi_finalize_current_message(master);
+
+ return ret;
+}
+
+/**
+ * spi_finalize_current_transfer - report completion of a transfer
+ *
+ * Called by SPI drivers using the core transfer_one_message()
+ * implementation to notify it that the current interrupt driven
+ * transfer has finised and the next one may be scheduled.
+ */
+void spi_finalize_current_transfer(struct spi_master *master)
+{
+ complete(&master->xfer_completion);
+}
+EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
+
/**
* spi_pump_messages - kthread work function which processes spi message queue
* @work: pointer to kthread work struct contained in the master struct
@@ -559,6 +651,7 @@ static void spi_pump_messages(struct kthread_work *work)
pm_runtime_mark_last_busy(master->dev.parent);
pm_runtime_put_autosuspend(master->dev.parent);
}
+ trace_spi_master_idle(master);
return;
}
@@ -587,6 +680,9 @@ static void spi_pump_messages(struct kthread_work *work)
}
}
+ if (!was_busy)
+ trace_spi_master_busy(master);
+
if (!was_busy && master->prepare_transfer_hardware) {
ret = master->prepare_transfer_hardware(master);
if (ret) {
@@ -599,6 +695,20 @@ static void spi_pump_messages(struct kthread_work *work)
}
}
+ trace_spi_message_start(master->cur_msg);
+
+ if (master->prepare_message) {
+ ret = master->prepare_message(master, master->cur_msg);
+ if (ret) {
+ dev_err(&master->dev,
+ "failed to prepare message: %d\n", ret);
+ master->cur_msg->status = ret;
+ spi_finalize_current_message(master);
+ return;
+ }
+ master->cur_msg_prepared = true;
+ }
+
ret = master->transfer_one_message(master, master->cur_msg);
if (ret) {
dev_err(&master->dev,
@@ -680,6 +790,7 @@ void spi_finalize_current_message(struct spi_master *master)
{
struct spi_message *mesg;
unsigned long flags;
+ int ret;
spin_lock_irqsave(&master->queue_lock, flags);
mesg = master->cur_msg;
@@ -688,9 +799,20 @@ void spi_finalize_current_message(struct spi_master *master)
queue_kthread_work(&master->kworker, &master->pump_messages);
spin_unlock_irqrestore(&master->queue_lock, flags);
+ if (master->cur_msg_prepared && master->unprepare_message) {
+ ret = master->unprepare_message(master, mesg);
+ if (ret) {
+ dev_err(&master->dev,
+ "failed to unprepare message: %d\n", ret);
+ }
+ }
+ master->cur_msg_prepared = false;
+
mesg->state = NULL;
if (mesg->complete)
mesg->complete(mesg->context);
+
+ trace_spi_message_done(mesg);
}
EXPORT_SYMBOL_GPL(spi_finalize_current_message);
@@ -805,6 +927,8 @@ static int spi_master_initialize_queue(struct spi_master *master)
master->queued = true;
master->transfer = spi_queued_transfer;
+ if (!master->transfer_one_message)
+ master->transfer_one_message = spi_transfer_one_message;
/* Initialize and start queue */
ret = spi_init_queue(master);
@@ -1205,6 +1329,7 @@ int spi_register_master(struct spi_master *master)
spin_lock_init(&master->bus_lock_spinlock);
mutex_init(&master->bus_lock_mutex);
master->bus_lock_flag = 0;
+ init_completion(&master->xfer_completion);
/* register the device, then userspace will see it.
* registration fails if the bus ID is in use.
@@ -1451,6 +1576,10 @@ static int __spi_async(struct spi_device *spi, struct spi_message *message)
struct spi_master *master = spi->master;
struct spi_transfer *xfer;
+ message->spi = spi;
+
+ trace_spi_message_submit(message);
+
if (list_empty(&message->transfers))
return -EINVAL;
if (!message->complete)
@@ -1550,7 +1679,6 @@ static int __spi_async(struct spi_device *spi, struct spi_message *message)
}
}
- message->spi = spi;
message->status = -EINPROGRESS;
return master->transfer(spi, message);
}